The disclosure relates to heat recovery steam generators and, more specifically, output manifolds for high cycling heat recovery steam generator systems.
Heat recovery steam generator systems may include an output manifold for aggregating flow and routing the working fluid to a steam turbine and/or other process demand. An HRSG may be fluidically connected to a plurality of header lines for directing fluid flow of low pressure, high pressure, and superheated steam through the stages of the HRSG. The output manifold contains and directs the flow of high temperature, pressurized fluids, such as superheated steam from the superheated steam lines among the header lines. Any given output manifold may have defined flow capacities, wall thickness, materials, and link assemblies for controlling and enduring thermal stresses. However, thermal stress from high cycling systems may increase component wear and decrease the life of the output manifold and/or its components.
Some output manifolds include a single output line receiving fluids directly from a plurality of header links that are connected to a plurality of header lines carrying heated fluids. The single output line is sized for the output capacity of the system and the needs of the downstream steam turbine or other process demand. The diameter, thickness, and material requirements of the single output line may increase both initial and replacement costs of the output manifold and/or require that the entire manifold be replaced in the event of wear or a failure.